This invention relates to door handle assemblies and, more particularly, to door handle assemblies for controlling the latch mechanism on vehicle doors.
Vehicle doors typically include a latch mechanism for latching and unlatching the door to the vehicle body, a handle assembly positioned on the door and operative to control the latch mechanism, and a lock mechanism to selectively render the handle assembly effective or ineffective to operate the latch. It is imperative that side impact against the vehicle, resulting for example from a collision, not result in the inadvertent movement of the handle of the handle assembly to a latch release position with consequent movement of the latch to an unlatched position and consequent inadvertent opening of the door. This in general is not a problem when the door is locked since in this case the door handle is either precluded from movement by the lock mechanism or the door handle is allowed to freewheel to its unlatched position but this movement is ineffective to move the latch to its unlatched position. However, when the door is unlocked, as is most typically the case in a moving vehicle, side impact can easily result in inertial movement of the door handle to its unlatched position with consequent unlatching of the latch mechanism, consequent opening of the door, and consequent discharge of unbuckled vehicle passengers from the vehicle.
Various attempts have heretofore been made to address the side impact problem and specifically to avoid inadvertent opening of the vehicle door in a side impact situation. In the most commonly employed arrangement, a heavy duty spring is employed in association with the door handle. The spring may be sized, for example, to preclude movement of the door handle to its open position in crash situations involving up to 30 G's of impact force. Whereas this arrangement satisfies the existing Federal motor vehicle safety standards with respect to side impact, it also results in a door handle that is very difficult to open because of the heavy duty spring employed in association with the door handle. This arrangement has the further disadvantage that the magnitude of the side impact force that the door handle assembly can withstand without inadvertent opening of the door is limited by the strength of the spring associated with the door handle so that, for example, if the door handle spring is sized to resist a 30 G impact force, any side impact force in excess of 30 G will result in opening of the door.
Various other arrangements have been proposed wherein inertial movement of a component of the door handle assembly upon impact has the effect of blocking the opening or unlatching movement of the door handle assembly. However, these inertial devices are complicated and expensive in construction, and require close manufacturing tolerances to ensure successful, consistent operation.